England's Rugby Football Union (RFU) have recommended that only players recorded as female at birth be allowed to play in women's rugby and will hold a vote on transgender participation next week.
The RFU said on Friday that it began a review of its existing policy in 2020 with a survey that received more than 11,000 responses. It said it held extensive consultation, studied scientific evidence and sought guidance from other sporting bodies.
The review concluded that peer-reviewed research provides evidence there are physical differences between people whose sex was assigned as male and those as female at birth.
It also found advantages in strength, stamina and physique brought about by male puberty which are significant and retained even after testosterone suppression, the RFU added.
"This science provides the basis of the recommendation that the inclusion of trans people assigned male at birth in female contact rugby cannot be balanced against considerations of safety and fairness," the RFU said in a statement.
"The recommendation is that until such time as new science is available, a precautionary approach is appropriate to ensure fair competition and safety of all competitors.
"The RFU Council have been provided with access to medical, scientific and social information so that it can consider this recommendation and the merits of any alternative approaches, including a case by case approval process."
The RFU said case assessment could result in some players not being permitted to participate in the female category.
"Therefore, the RFU Council will vote on a recommendation for a policy change for contact rugby to only permit players in the female category whose sex recorded at birth was female.
"In the male category it is proposed that players whose sex recorded at birth is female may play if they provide their written consent and a risk assessment is carried out."
The vote takes place next Friday.
World Rugby instituted a ban on transgender players competing at the elite level of the women's game last year, citing safety concerns.
World Athletics and FIFA are among a number of federations reviewing their guidelines on the involvement of transgender athletes following world swimming body FINA's ruling to ban anyone who has been through male puberty from elite women's competitions.